利用微波技术快速诊断金属污染物对微生物群落的影响

More recently, soil pollutions becoming more and more severe. Therefore, it is a key importance to in-situ rapid diagnosis of soil properties to evaluate the environmental risk. It is a burgeoning challenge to R&D to apply a potential theory and technology to assess the degree of contamination in local polluted soil field. As a composite dielectric media, in soil, in particular containing metal pollutants, microbial is representative to the soil quality. In this proposal, through dipole orientation of soil components under applied external electro-magnetic field near microwave frequency range that enables to their dielectric properties (i.e. dielectric constant and conductivity) responsive to microwave signals, the influence of metal pollutants on microbial community were investigated, in combination with its corresponding mathematic modeling, to rapidly in-situ diagnosis and analyze the contaminated soil, hence for the quick environmental risk assessment. New measurement system in the proposal is based on close ended coaxial probe microwave technology for testing the soil, which features low cost, rapid measurement, and comparatively easy samples preparation, etc. Moreover, it is nearly no such literature reports on rapid measurement on the dielectric properties of bacteria cell in the soil. Implementation of this proposal would greatly facilitate the rapid on-site assessment on the known-source metal polluted soil, in particular under urgent situations, which is anticipated to satisfy the “blank” of theory and technologies in this area in China.

近年来土壤污染日益严重，进行土壤的原位快速检测对环境风险评估非常重要，污染区的快速检测相关理论与技术的研究方兴未艾。土壤是一种复合电介质材料，在金属污染土壤中，微生物是土壤污染状况的典型表征生物。本项目拟通过土壤组分在微波频率的外加电磁场作用下发生偶极子取向，使其介电特性（如介电常数、电导率等）发生响应行为的原理，研究金属污染物对微生物群落的影响，并构建出对应的数学关系模型，以期对土壤进行原位快速诊断分析, 快速给出环境风险评价结果。该项目拟采用闭路同轴探头微波技术系统对土壤进行检测，该新系统具有检测成本低廉、检测速度快，检测样品多样且无需样品制备等优点。对于现场土壤中的细菌细胞的介电性质进行快速检测技术，鲜有相关文献报道。本项目的开展将大大有利于对已知金属污染源，尤其是突发性土壤污染的现场快速检测评估的实施，填补国内该领域研究的理论与技术上的空白。

全球环境极速退化，土壤和水环境中生态和环境问题加剧，对快速收集准确地环境监测数据的需求迫在眉睫。在这种背景下,急需一种智能传感器来监测数据。微波传感器具有制造成本低、体积小、低功耗等特点,能够满足快速检测环境中物质介电常数的变化从而监测环境中污染物质的浓度变化，可以应用于在土壤污染、生物安全、食品安全、水生态问题等领域。 . 在本项目中，我们研制了三种不同类型的微波探头来满足不同的环境监测要求。这三种探头分别为双端口同轴微波探头、开放同轴微波探头以及PCB印制微波探头。这三种探头可以较好的应用于土壤中的微生物、有机污染物监测，食品安全方面的监测等。在利用双端口同轴微波探头检测土壤中的重金属污染方面取得了较好的结果，达到了项目开题所需要的目标要求。该技术通过检测物质的介电常数的变化来反应出物质的浓度的变化，从而达到检测环境污染物的目的。通过一系列的实验可以证明该技术可以检测不同物质的介电常数等相关性质，证明了设计的探头的实用性以及计算方法的准确度与灵敏度，同时也反应了该方法是一种富有应用前景的测量方法，值得我们进一步的探索研究。